Network: Parse host physical NIC MAC address for storing in device co…

…nfiguration (#14905)

Fixes #14879.

This PR adds parsing of the host physical NIC MAC address, allowing
`agent.nic_config` to be set to `true` for physical NIC devices. I've
also updated the metadata and included a small completion fix for a bug
I discovered while testing this.

Summary of changes:
- Fixes conditional completions for `lxc config device add`.
- Updates metadata for physical NIC `hwaddr` config key.
- Updates the physical NIC `Start` method to retrieve host physical NIC
MAC address and store in device config (for use in `addNetDevConfig` ->
`writeNICDevConfig`).

doc/metadata.txt

@@ -1007,7 +1007,7 @@ This option specifies whether to register the VLAN using the GARP VLAN Registrat
 ```
 
 ```{config:option} hwaddr device-nic-physical-device-conf
-:defaultdesc: "randomly assigned"
+:defaultdesc: "parent MAC address"
 :managed: "no"
 :shortdesc: "MAC address of the new interface"
 :type: "string"

lxc/config_device.go

@@ -107,12 +107,13 @@ lxc profile device add [<remote>:]profile1 <device-name> disk pool=some-pool sou
 			}
 		}
 
-		if len(args) == 1 {
+		// The second positional argument is used for the device name, so we provide device completions for the third positional argument.
+		if len(args) == 2 {
 			return c.global.cmpInstanceAllDevices(toComplete)
 		}
 
-		if len(args) == 2 {
-			return c.global.cmpInstanceAllDeviceOptions(args[0], args[1])
+		if len(args) == 3 {
+			return c.global.cmpInstanceAllDeviceOptions(args[0], args[2])
 		}
 
 		return nil, cobra.ShellCompDirectiveNoFileComp

lxd/device/nic.go

@@ -161,14 +161,22 @@ func nicValidationRules(requiredFields []string, optionalFields []string, instCo
 		//  defaultdesc: `false`
 		//  shortdesc: Whether to use GARP VLAN Registration Protocol
 		"gvrp": validate.Optional(validate.IsBool),
-		// lxdmeta:generate(entities=device-nic-{bridged+macvlan+sriov+physical+ovn}; group=device-conf; key=hwaddr)
+		// lxdmeta:generate(entities=device-nic-{bridged+macvlan+sriov+ovn}; group=device-conf; key=hwaddr)
 		//
 		// ---
 		//  type: string
 		//  defaultdesc: randomly assigned
 		//  managed: no
 		//  shortdesc: MAC address of the new interface
 
+		// lxdmeta:generate(entities=device-nic-physical; group=device-conf; key=hwaddr)
+		//
+		// ---
+		//  type: string
+		//  defaultdesc: parent MAC address
+		//  managed: no
+		//  shortdesc: MAC address of the new interface
+
 		// lxdmeta:generate(entities=device-nic-{ipvlan+p2p+routed}; group=device-conf; key=hwaddr)
 		//
 		// ---

lxd/device/nic_physical.go

@@ -137,6 +137,8 @@ func (d *nicPhysical) Start() (*deviceConfig.RunConfig, error) {
 	// pciIOMMUGroup, used for VM physical passthrough.
 	var pciIOMMUGroup uint64
 
+	var hwaddr string
+
 	// If VM, then try and load the vfio-pci module first.
 	if d.inst.Type() == instancetype.VM {
 		err = util.LoadModule("vfio-pci")
@@ -200,6 +202,12 @@ func (d *nicPhysical) Start() (*deviceConfig.RunConfig, error) {
 			}
 		}
 	} else if d.inst.Type() == instancetype.VM {
+		// Try to get MAC address of the parent interface.
+		hwaddr, err = NetworkGetDevMAC(saveData["host_name"])
+		if err != nil {
+			return nil, err
+		}
+
 		// Try to get PCI information about the network interface.
 		ueventPath := fmt.Sprintf("/sys/class/net/%s/device/uevent", saveData["host_name"])
 		pciDev, err := pcidev.ParseUeventFile(ueventPath)
@@ -245,6 +253,7 @@ func (d *nicPhysical) Start() (*deviceConfig.RunConfig, error) {
 				{Key: "devName", Value: d.name},
 				{Key: "pciSlotName", Value: saveData["last_state.pci.slot.name"]},
 				{Key: "pciIOMMUGroup", Value: fmt.Sprintf("%d", pciIOMMUGroup)},
+				{Key: "hwaddr", Value: hwaddr},
 			}...)
 	}
 

lxd/metadata/configuration.json

@@ -1147,7 +1147,7 @@
 					},
 					{
 						"hwaddr": {
-							"defaultdesc": "randomly assigned",
+							"defaultdesc": "parent MAC address",
 							"longdesc": "",
 							"managed": "no",
 							"shortdesc": "MAC address of the new interface",